Organic electroluminescent display device

Abstract

An organic EL display device includes an organic EL element having a first light-emitting portion, a second light-emitting portion, an n-type charge-generation layer, and a p-type charge-generation layer. The first light-emitting portion has a first light-emitting layer and a hole-injection layer. The first light-emitting layer is formed between an anode and a cathode. The hole-injection layer is made of amorphous carbon and in contact with the anode. The second light-emitting portion has a second light-emitting layer, which is formed between the first light-emitting portion and the cathode. The n-type charge-generation layer is formed between the first and second light-emitting portions. The n-type charge-generation layer is in contact with the first light-emitting portion. The p-type charge-generation layer is made of amorphous carbon and formed between the n-type charge-generation layer and the second light-emitting portion. The p-type charge-generation layer is in contact with the second light-emitting portion.

What is claimed is: 
     
       1. An organic EL display device including an organic EL element, the organic EL element comprising:
 an anode electrode made of a conductive material; 
 a cathode electrode made of a conductive material; 
 a first light-emitting portion having a first light-emitting layer and a hole injection layer, the first light-emitting layer being formed between the anode electrode and the cathode electrode to emit light in response to a potential difference applied between the anode electrode and the cathode electrode, the hole injection layer being made of amorphous carbon and in contact with the anode electrode; 
 a second light-emitting portion having a second light-emitting layer, the second light-emitting layer being formed between the first light-emitting portion and the cathode electrode to emit light in response to the potential difference applied between the anode electrode and the cathode electrode; 
 an n-type charge generation layer formed between the first light-emitting portion and second light-emitting portion, the n-type charge generation layer being in contact with the first light-emitting portion to supply electrons to the first light-emitting portion; and 
 a p-type charge generation layer made of amorphous carbon and formed between the n-type charge generation layer and the second light-emitting portion, the p-type charge generation layer being in contact with the second light-emitting portion to supply holes to the second light-emitting portion. 
 
     
     
       2. The organic EL display device according to  claim 1 , further comprising
 a metal layer, made of metal, between the n-type charge generation layer and the p-type charge generation layer. 
 
     
     
       3. The organic EL display device according to  claim 2 , wherein
 the metal layer is made of a material selected from the group consisting of Ag alloy, Al alloy, Ag, and Al. 
 
     
     
       4. The organic EL display device according to  claim 1 , wherein
 the amorphous carbon is formed as a layer by sputtering in an atmosphere including argon gas.